Two long-standing flakes in system_tests, both timing:
- security: the ban period was set to one second, but the test makes a
hundred more requests before it checks that a valid password from the
banned address is refused, so under load the ban had already expired.
Five seconds, and the expiry check sleeps six.
- task: a task scheduled one second out was queried for straight away,
and under load the query landed after the task manager had run and
removed it. Three seconds.
Seven consecutive system_tests runs, neither recurred.